The applet game controls do not function and the game can't play. This issue is specific to FF 2.x on Solaris platform. It works as expected on Windows/FF 2.x.
The problem can't be reproduced if using the new plugin with FF 3.x on Solaris.

Tested Platform: Solaris 9, 10 (sparc, x86)
       Browser: FF 2.x
       jre: 6u12-b03

Steps to reproduce:
1) On solaris machine, configure FF 2.x with plugin 6u12.
2) Use Ff 2.x, browser http://ww5.freearcade.com/Nobby.jav/Nobby.html?s=highscore
3) The game applet should be loaded.
4) Click 'START' button to play the game.

If you can't use any arrow key controls as mentioned in the game instructions, then the issue is reproducible. Try the same game on Windows/ FF 2.x/ jre 6u12-b03 to see the expected behaviour.